Fix debuginfo rpm build on RHEL6
Fix debuginfo rpm build on RHEL6

debugedit attempts to re-write header search paths in Perl DSOs like
PMDA.so and miscalculates the length of the old vs new path and
aborts the build - just use relative paths to avoid this problem.

aeg-aeg/pcpfans,andyvand/cygpcpfans,edwardt/pcp,edwardt/pcp,edwardt/pcp,aeg-aeg/pcpfans,edwardt/pcp,mbaldessari/pcp,ryandoyle/pcp_original,aeg-aeg/pcpfans,wuliming/pcp,ryandoyle/pcp_original,adfernandes/pcp,adfernandes/pcp,tjanez/pcp,aeg-aeg/pcpfans,ryandoyle/pcp_original,edwardt/pcp,mbaldessari/pcp,aeg-aeg/pcpfans,ryandoyle/pcp_original,prasincs/pcp,adfernandes/pcp,aeg-aeg/pcpfans,andyvand/cygpcpfans,ryandoyle/pcp_original,tjanez/pcp,andyvand/cygpcpfans,tjanez/pcp,andyvand/cygpcpfans,mbaldessari/pcp,edwardt/pcp,mbaldessari/pcp,ryandoyle/pcp_original,andyvand/cygpcpfans,edwardt/pcp,wuliming/pcp,wuliming/pcp,mbaldessari/pcp,adfernandes/pcp,edwardt/pcp,prasincs/pcp,prasincs/pcp,prasincs/pcp,tjanez/pcp,tjanez/pcp,tjanez/pcp,ryandoyle/pcp_original,aeg-aeg/pcpfans,wuliming/pcp,adfernandes/pcp,prasincs/pcp,prasincs/pcp,andyvand/cygpcpfans,mbaldessari/pcp,adfernandes/pcp,prasincs/pcp,andyvand/cygpcpfans,ryandoyle/pcp_original,wuliming/pcp,prasincs/pcp,aeg-aeg/pcpfans,tjanez/pcp,wuliming/pcp,andyvand/cygpcpfans,wuliming/pcp,tjanez/pcp,adfernandes/pcp,wuliming/pcp,adfernandes/pcp